Microplastics in feces and pellets from yellow-legged gull (Larus michahellis) in the Atlantic Islands National Park of Galicia (NW Spain)

The Atlantic Islands National Park (AINP) in Galicia (NW of Spain) are host to large colonies of yellow-legged gulls (Larus michahellis). Here, we aimed to provide baseline data for the presence of microplastics (MP) in feces and pellets regurgitated of these resident yellow-legged gulls within this unique ecosystem. MP particles found in the samples were of five shapes (fiber, fragment, foam, film and rubber) and the predominant color was blue. The main plastic polymers identified by Raman spectroscopy were polypropylene and cellulose. The average size of the MP particles in the regurgitations was larger than that in the feces. Considering the population of Larus michahellis in the AINP, our estimates suggested an annual deposition of approximately 32.2 million of MP particles from feces and regurgitated pellets in the area.